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CHARLES H. FOWLER, OF ROXBURY, MASSACHUSETTS.

Letters Patent No. 78,520, dated June 2, 1868.

IMPROVEMENT IN LATER-TOOL HOLDER.

TO ALL 'IO WHOM THESE PRESENTS SHALL COME;

Beit known 'that I, CHARLES H. FowLnn, of Roxbury, in the county of Norfolk, and State of Ma'ssachw setts, havev invented a newand useful Improvement in Cutting-Tools for Machinists Lathes; and do hereby declare the following to be a full, clear, and estactdescription thereof,`due reference beinghad to the accompanying drawings, making part of this specification, and in whichi Figure 1 is a longitudinal section, and

IFigure 2a horizontal section of my invention.

Figure 3 is a side elevation of its chuck or tool-holding thirnble,"tov be hereinafter referred to.

My invention may, in some respects, be considered as a combined tool and tool-holder, and relates to means for applying the tool of a metal-turning or engine lathe in such man-nei' as to obviate the necessity ofreforging the tool, which, under the present fo'rm of construction, must ,be done at short intervals of time.

The invention consists in a metallic bar, having its inner end enlarged and recessed, and carrying a tapering or double cylindre-conical tube, the tapering portions ofsuch tube being split inthe manner of ordinary small drill-chucks used in most machine-shops, the bore of such cylinder being square or rectangular, and carrying a cutting-tool or bar, constituting the turning-tool, substantially as hereinafter explained.

In the drawings above mentioned, A denotes a metallic bar, of suitable size and shape, according to the proportions of the piece of metal to be turned or reduced, this bar A, when in use, being inserted in a horizontal position within the slide-rest of the lathe, in the same manner that the ordinary turning-tool is now applied.

As usually constructed, this ordinary Atool has its' cutting portion forged upon one end of it, as shown in iig. 4 of the drawings, and. as often as the cutting-tool requires renewing it must be reforged.

In carrying out my invention, I form, in the inner end of the bar A, a vertical cylindrical passage or opening, a, ,the upper portion of which is contracted in diameter, and tapering, the lower portion thereof being formed with a female screw, 6,'i'nto which is screwed a male screw, formed upon the circumference of a sleeve or hollow nut, c,-the upper portion of the bore of this sleeve for about one-half its length being tapering, but in an inverse direction from that ofthe passage abefore mentioned that is, the passage aiscontracted toward its'top and the bore of the sleeve c toward its bottom, this being for the purpose of receiving between them a hollow plug or chucvk-g d, which is` a cylindrical tube, tapering'at each end, and having a rectangular bore, e, for receiving a-steel rodhf, which constitutes the cutting-tool of the device.

-The plug d is'split u-pon each end, after the manner of ordinary small drill-chncks,or so that when it is compressed within or between the bores of the bar A and the screw c, it shall take a firm gripe of the cuttingtoolf, and retain it rmly in position while performing its work.

As the tool isreduced or worn down, the screw-sleeve or hollow nut c is to beloosened, and the tool raised to the desired height. v y

By means of my invention above described, frequent reforging of the tool is avoided, this economy of time being directly dependent upon the length of the cutting-bar employed.

Another advantage of my invention is the fact that whereas, in the old mode of forging the tool, a much larger piece of steel is. wasted, as it :is gradually reforged and wornout, and a much llarger number are also wasted than in my mode, it will be seen that a. great economy of metal is effected.

I claim, as an improved tool-holding device for metal-turning lathes, Jvc., the combination and arrangement of the bar A, screw-sleeve or'hollow nut c, und double tapering tube d, the whole being arranged and operating as herein shown and described. i

CHARLES. H. FOWLER.

Witnesses FRED. CURTIS, EDWARD GRIFFITH. 

